Sinclair Users Network

S.U.N.

SINCLAIR USERS'' NETWORK
2178 OAK BROOK CIRCLE
PALATINE, ILLINOIS 60074
(312) 934-9375

THE USERS GROUP FOR TIMEX k SINCLAIR COMPUTERS

APRIL 1983

What’s
U nder
the S.U.N

ATTENTION NETWORKERS: We have revised our
charter slightly to accomodate our increased
services to members. Newsletters will now be
published six times yearly (Jan., Mar., May,

July, Sept., Nov.) with bulletins still
mailed in the months between. These go to
the post office from the 20th to the 25th of
the month prior to issue so if you get them
late please complain in writing so that we
may protest formally to the post office.

Memberships are no longer on a Jan. 1 to Dec.

31 format so if you join in April of '83 you are a S.U.N. member
March 31, 1984. Other changes are those who get new members into

will get an extra 200 lines credit (so make sure they give us your
and requesting programs from the exchange to be taped on our cassett
now cost $2.00 rather than $2.50. Write or phone if you have commen
questions on the revisions.

'till

S.U.N.

name)
e wi 1 1
ts or

CO-OP: We stock: blank C-20 certified data tapes at $0.71 each, labels at

$0.01, boxes at $0.15; TIMEWRITER a word processor for all popular under

$150 printers is $10.00; the arithmetic tutor MATH MAESTRO sells for $8.00

each to members; line filters to protect your ZX/TS from voltage spikes and

crashes still go for $14.95 each. Shipping charges are: cassettes 10 for

$1.00, $0.05 each for additional tapes; no shipping on boxes if they are

purchased with cassettes, $0.05 each over the cassette count (no shipping
charges for labels with cassettes; $1.00 each for TIMEWRITER, MATH MAESTRO,
and the line filter. Mornae's language tapes, LINGO, as reviewed in March
now sell for $10.95 each to members - include your I.D. number, shipping'*6/#
charges, and Illinois residents add sales tax to all co-op purchases. y—

ERRATA: The suite number for A+ Associates, the company that provided us

with the free coding form in March, is 3119, not 1119. To initialize the
program of the month in March, add line 85 as a (STOP), then (GOTO) line
20. Following this delete lines 20 through 85 then (GOTO) your (SAVE)

routine in line 1180. As an alternative, you could enter lines 20 through

80 in the immediate mode.

ES-II

TO BUY OR NOT TO BUY ?

- System Switch Box by Electronic Shop

A chief cause of aggravation to ZX/TS owners is the constant need to be
changing plugs. When you (SAVE) a program, you must only plug in the leads
from "mic" to "mic"; when you (LOAD) a program, only the "ear" to "ear"
leads should be connected; crashes, of course, can only be cured by pulling
the 9 volt power leads. The ESI I from Electronic Shop solves these prob-
1 ems.

continued on next page

ZXFORTH by the Forth Dimemsion

For those who have worked and struggled to achieve a mastery of BASIC, and
realize its rewards, here is a new computer language offering another
challenge but even more productivity from your ZX/TS computer. FORTH, a
language now 14 years old, is unique in its ability to allow the programmer
to build program solving modules then assign them user—defined names. Any
time the programmer needs a new routine, it is easily built and the name is
then added to the FORTH dictionary. The guiding principle behind this most
flexible of all computer languages is the axiom: KEEP IT SIMPLE. Simplici¬
ty breeds elegant solutions and it is this beauty that brings novices to
this language into what is called the FORTH community.

ZX-FORTH comes to you on a cassette with more than 68 pages of documenta¬
tion. This software package contains a bibliogrophy of FORTH reference
works for those new to this powerful language. After loading, the system
allows over 6K of workspace for programming using a 16K RAM pack. For
those with over 16K, facilities are provided to increase the size of the
workspace depending on your needs and system capabilities. This software,
although written to read from and write to cassettes, may be patched into
a disc operating system with simple routines less than 40 bytes long. This
program complies with the FORTH-79 standard, the sole exceptions being the
replacement of the number sign with the symbol for the British pound, the @
sign with a question mark, the exclamation point with *, an apostrophy with
the word "tick", and "[■ and "3" with *(" and ">". This standard employs
stack oriented mathematics which uses a last-on / first-off structure.
Although different from algebraic logic, it is similar in structure to the
Reverse Polish Notation used by Hewlett-Packard calculators. To add 3 to 9
and then multiply by 10 you would type in 10, 3, 9, ♦ , X; a final period
prints out the correct answer. All arithmetic is integer and may use
single or double precision for twice the potential accuracy, and 5 times
the speed of your ZX/TS using BASIC. Double precision gives you a range of
numbers greater than 4 billion! You may calculate in base 10 or base 16 or
choose any base from 2 to 36. Conditional branching is provided and tests
generally change the top number on the stack as a flag. Unlike our stand¬
ard ZX/TS BASIC, ZX-FORTH supports "ELSE" for a second level of conditional
execution. Looping may also be tested in a manner dissimilar but superior
to the method used by the Sinclair ROM. Programming in ZX-FORTH is ex¬
pedited by auto-repeat on the keys and two different editing facilities.
Saving code onto cassette is much faster than ZX/TS BASIC due to both the
self-compi1ing feature of ZX-FORTH as well as the ability to use ":LOAD
FAST LOAD;" when storing your programs! Mhile using ZX—FORTH you may enter
BASIC, if for some strange reason you should want to, by typing "BYE" and
pushing (ENTER). Going back to ZX-FORTH is done through a simple (USR)
call. Upon returning, all variables, constants, operators, and the dic¬
tionary will be found intact. To protect new words that you've added to the
dictionary from being lost you simply change the boundaries of the "FENCE".
This system has built in back-up routines. Nhen making duplicate copies
all information desired is retained. Customized protected dictionaries are
saved along with the basic FORTH operating system.

This most impressive software package truly brings the power of a full-
fledged computer to your ZX/TS. This review does little justice to the
immense capabilities of ZX-FORTH for engineering, text-handling, and games
(the package includes an unbelievably fast game called BREAKFORTH). This
software sells for $42.95 plus $2.00 for domestic shipping and handling,
$7.00 for foreign. You may order from THE FORTH DIMENSION, 1451 Union St.,
Middletown, PA, 17057. If you're serious about computing this is a "must-
have" product.

ES-II continued

This unit, in a black case with silver trim matching the ZX/TS computer, is
a compact 4" X 2" X 2" device that comes with all the leads necessary to
plug it in and use. It employs high quality jacks and switches and its us'
will prevent wear and tear on the ZX/TS jacks that will severely shorten
your computers useful life. An LED indicator not only informs you of your
ZX/TS being inadvertently left on, a fine way to burn up your computer, but
by watching for flickering you can spot fluctuating house current that will
cause problems to both your computer and other electrical appliances! The
jacks on the switch-box are color coded to minimize confusion during set¬
up. This is a high-quality product that will add years of life to your
computer. It may be ordered from: Electronic Shop, 912 East 26th St.,
Kearney, NB, 68847. The price is $26.95 plus $2.60 for shipping and han¬
dling. S.U.N. members include your I.D.# for a $3.06 discount.

FULL SIZE KEYBOARD by Memotech

In the search for different ways to enhance the utility of ZX/TS computers
S.U.N. has analyzed many devices. One of the most attractive and practical
is Memotech's full size keyboard.

Unlike most other expansion keyboards, using the Memotech device will not
void your computer's warranty. Connecting this unit is simplicity itself.
You simply turn off your ZX/TS, remove your 16K RAM, if you use one, and
then plug the Memotech keyboard's buffer into the expansion slot of your
computer. You may now plug your RAM pack or any other device into the edge
connector on the back of the keyboard buffer. One of the nicest things to
be found from this system is that you will have fewer crashes due to RAM^
pack wobbles as the connection from the computer to the keyboard buffer t
the RAM pack is more secure than from the computer to the RAM pack alone!
The connection from the buffer to the keyboard is through an II inch long
ribbon cable which is internally fastened on both units. The keyboard uses
standard plunger keys that feel as nice as the keys on any personal compu¬
ter, whether it costs $200 or $2000. An excellent feature of this product
is the second space key located on the top row just to the right of the
(DELETE) key. This greatly increases the speed when you change lines and

correct errors in your programs or text entries. What may be the best

argument for the purchase of this unit is the ability to use both the

Memotech and the standard ZX/TS keyboard simultaneously. This opens up

seemingly limitless opportunities for two person interactions, both in
games and in education. Last, but definitely not least, the appearance of
this product is up to Memotech's usual high standards. Two versions of the
case have been used: a metallic blue design with silver trim and matching

blue keys and a black unit, designed to match the ZX/TS as well as Memo¬
tech's other peripherals, with ivory keys and silver trim. Either^ unit
will improve the looks of your computer. We did find the keyboard to
interfere slightly with a TV used as a monitor but found this to be both
minimal and acceptable, at the worst.

To sum, this is a useful product, mid-range in price, with several good
reasons to recommend its purchase. To use it requires no mechanical or
electrical skills beyond the ability to plug in a RAM pack. It expands the
utility of the computer in business, entertainment, and education. The
appearance of the keyboard enhances that of your computer. The cost

this device is $99.95 plus $4.95 for shipping and handling. You may ordfe

from Memotech Corporation, 7550 West Yale Ave., Denver, CO 80227. VISA
and MasterCard holders may dial 1<800)662-0949.

SINCLAIR USERS NETWORK
2170 OAK BROOK CIRCLE
PALATINE, ILLINOIS 68974

Bulk Rale
U. S. Postage

PAID

Permit 77

Palatini, It